21. What is the difference in ACL on ASA than on Router?
In router, if we delete one access-control entry whole ACL will be deleted. In ASA, if we will delete one access-control entry whole ACL will not be deleted.

22. Name some concepts that cannot be configured on ASA?
Line VTY cannot be configured on ASA.
Wildcard mask concept is not present in ASA.
Loopback cannot be configured on ASA.

23. What is the command to capture packets in ASA?
To capture packet from inside interface:- # capture abc interfacer inside
To see it:- # sh capture abc

28. What is Tranparent Firewall?
In Transparent Mode, ASA acts as a Layer 2 device like a bridge or switch and forwards Ethernet frames based on destination MAC-address.

29. What is the need of Transparent Firewall?
If we want to deploy a new firewall into an existing network it can be a complicated process due to various issues like IP address reconfiguration, network topology changes, current firewall etc. We can easily insert a transparent firewall in an existing segment and control traffic between two sides without having to readdress or reconfigure the devices.

30. What are the similarities between switch and ASA (in Transparent mode) ?
Both learns which mac addresses are associated with which interface and store them in local mac address table.